Gas Overflow at the pump....
 

My car has an obvious problem with the auto-shutoff on the gas pump. Is this a problem with everyone else's car? I'm sure it has something to do with the shape of the filler neck and/or the air escaping from the tank while the gas is going in......but damn......I'm tired of having to remember to fold up a paper towel and put it below the nozzle everytime....or be faced with an overflow surge that comes out of the hole, down the fender, hits the tire, then makes it all the way around the wheel to sit at the bottom. WTF? I'm OVER IT! My DD Protege never overflows......and after it shuts off, I can usually squeeze in another gallon! I'm thinking that the RX-8 has a vent in the top of the gas tank that allows air to escape while you're filling it with gas..... so if there is air building in the tank as I'm filling up and the fuel makes its way all the way up to the filler neck, when the air in the tank has to escape it pushes the fuel at the top up and out. Does that make sense? Anyway, anyone know a fix for this? Or can anyone tell me if there is indeed a vent in the top of the tank? Any help is greatly appreciated.

I've never heard of anyone having that problem with the RX8. Does this just happen at your favorite gas station or all of them?
Don't try to "squeeze in another gallon". The pollution control system sucks the fumes of the top of the tank through a charcoal canister. If you fill the car to the neck, raw gasoline will be sucked into and pollute the canister. This will ruin it.

Happens to me too, day one since I bought the car.

It seemed to go away after a while though. And to second what Alnielsen said, once it clicks your full, anymore and you have overflow.

It still happens to me every now and then, but only at gas stations where the gas pumps ridiculously slow.

This happens at ALL gas stations......even in other states. I've never tried to squeeze in any more gas in the 8 because on the VERY seldom occasion that it doesn't overflow, I know that it's already filled to the rim. I have also tried holding the nozzle with my hand and cutting it off when it gets to the top but by the time I hear it getting full and I stop it, it 's already too late and the excess air surge pushes fuel out.

I had it happen once because the gas station was very low on fuel and the gas was being pumped too slow for the shutoff to work. Wasnt my 8's fault.

I've had it happen at a couple stations where the gas filled up really fast, when i fill it by hand I don't squeeze it all the way towards the end, the slower gas flow (but still fast enough to trigger the shutoff) kept it from overflowing..

I've seen this complaint from time to time. Usually a result of a problem with the anti-rollover valve which is designed to prevent fuel leak if the car is rolled.

My rx8 does the same thing at every gas station I've been too. I've made it a habit to stuff a couple of paper towels underneath the fill-hole to catch spilled gas.

It happens to me a fair amount of the time if the pump is set to full speed. Depends on the gas station. I usually fill up when I need about 10 gallons. I'll start at full speed, then cut back to the lowest setting when it gets to about 8 or 9. I don't think I've had it overflow with a pump at the lowest speed.

There have been a bunch of threads on this, so it's not that rare a problem.

Ken

It's not normal; no car should habitually leak gas for any reason. Have the dealer fix it.

As some people mentioned earlier it is the anti spill feature, in case of a rollover. I had this issue with my 8 from the very beginning. My mechanic, first, replaced the filler tube and that didn't help any. He contacted MAZDA and they couldn't think of any thing. He remembered that some 6s had this same issue so MAZDA said to replace the fuel tank; haven't had the overflow problem since.

Same here....
 

I do the same thing too. My gas overflows when I let the auto shut off stop the flow. What I normally do is barely squeeze the trigger when it gets to around 12.5 gallons. This slows the flow enough so that it doesn't rush out when it reaches the shut off sensor.

I have the same problem. Somewhere I read that the fuel tank needed to be replaced, but a search shows another possible solution: https://www.rx8club.com/trouble-shoo...solved-200520/

"I took my ’07 to the dealership for problems with gas overflow when fueling up at the pump (pump would click off when full, but would a gush of fuel, or, in one case, did not click off at all). Service writer said they called Mazda and there is a new fix. The service ticket says “called q/a reference #675666 and they have an updated part for inside the fuel tank for the suction hose between the two sides of the tank." Was done under warranty.

No problems now with overflow."

Hmmm. Have this problem as well, just never gotten annoyed enough with it to fix it. Wish there was more documentation on that "part for inside the fuel tank". May just have to do some exploratory surgery.

Thread bump. I am experiencing this issue on an 06 with low miles, and like everyone else I have dealt with it by filling up slowly. Has anyone actually seen what this part is or if it is serviceable without replacing the fuel tank?

Judging by comment post #13, it almost seems like 42-61X hose with the end connector labeled X might be the culprit. I have never seen the fuel tank or the inside of one in person, it is hard for me to say which parts on this diagram are actually inside the tank.

I have also thought about taking the fill vent tube off if it has one and clearing it out with pressurized air, maybe spiders have built a nest in their over time?

https://cimg3.ibsrv.net/gimg/www.rx8...60b74d5eb4.png